Migrate Kafka messaging telemetry to semconv v1.43 preview

[trask]

Depends on #19233.

Phase 1 baseline: fd4f3284dbb9d51614a4bb70b0258166d7b3dbff.

Scope

Migrates the Kafka messaging owner and its Kafka clients, Kafka Connect, Kafka Streams, Spring Kafka, Reactor Kafka, and Vert.x Kafka coverage to the semantic-conventions v1.43 messaging contract behind preview selection.

• Uses Kafka operation names send, poll, and process for v1.43 spans.
• Uses operation-first v1.43 span names.
• Changes pull/poll RECEIVE spans to CLIENT while keeping PROCESS spans CONSUMER.
• Emits messaging.kafka.consumer.group in old mode and messaging.consumer.group.name in v1.43 mode.
• Preserves Kafka offset dual emission and routes client IDs through the shared messaging extractor.
• Preserves propagation, links, suppression, listener topology, and old/default output.
• Adds staged testV3Preview tasks to the actual test owners and representative /dup coverage.

Selector behavior

• Default/unset: old 2.x messaging telemetry only.
• otel.semconv-stability.preview=messaging with otel.instrumentation.common.v3-preview=true: v1.43 telemetry only.
• otel.semconv-stability.preview=messaging/dup: both old and v1.43 attribute sets, with v1.43 single-valued span names and kinds.

Validation

Ran sequentially:

• Kafka clients 0.11: test, testV3Preview, and focused testBothSemconv
• Kafka clients 2.6 library: test and testV3Preview
• Kafka Streams: test and testV3Preview
• Kafka Connect: test and testV3Preview
• Spring Kafka: test and testV3Preview
• Reactor Kafka: test and testV3Preview
• Vert.x Kafka 3.6, 4.x, and 5.x: test and testV3Preview
• Spotless checks for every touched module
• git diff --check

While #19233 remains open, review should consider only commits and files after the recorded Phase 1 baseline fd4f3284dbb9d51614a4bb70b0258166d7b3dbff.

[opentelemetry-pr-dashboard]

Pull request dashboard status

• Status: Closed.

[trask]

Superseded by #19270 (Kafka clients and Connect core) and #19271 (Kafka Streams, Reactor Kafka, Spring Kafka, and Vert.x Kafka coverage). The preserved source head is 079681957d54d2b7e67a7bcd99e2953445583a19.